Bosch MAF Sensor ebay cheap for S'Charger
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http://cgi.ebay.com/ebaymotors/Porsc...#ht_1071wt_941
Anyone know if these can be made to work on an S2 with appropriate signal conversion. I could quite easily develop the appropriate transfer function using an interceptor between the MAF and ECU.
The purpose is to be able to run with a supercharger.
Anyone know if these can be made to work on an S2 with appropriate signal conversion. I could quite easily develop the appropriate transfer function using an interceptor between the MAF and ECU.
The purpose is to be able to run with a supercharger.
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The DME looks for a signal between 0-5V. The trick, of course, is getting the correct voltage to match the value the DME expects for that air flow using the AFM. But if you can do an arbitrary translation using an interceptor, what could be the problem? Sorry if I'm being dense.
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As it is for a 4.5l turbo engine, it would be rated for a much higher airflow. Not sure if the range/sensitivity would be appropriate for the S2.
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When supercharging the 944S2, there are obstacles in the ECU that you must get around way before you get to the VAF to MAF conversion.
Using a MAF then converting the signal to look like the stock VAF will gain you nothing (except for the free flow becuase of the larger ID of the MAF). However you still have the limitations of the factory VAF.
If you are boosting the S2, and doing all of the ECU work yourself, you will have better luck running with the VAF to start with. Once you get around the road blocks put in place by the Bosch/Porsche engineers , you'll have a better luck converting to a MAF. Of course this means rewriting the code to use the MAF.
Using a MAF then converting the signal to look like the stock VAF will gain you nothing (except for the free flow becuase of the larger ID of the MAF). However you still have the limitations of the factory VAF.
If you are boosting the S2, and doing all of the ECU work yourself, you will have better luck running with the VAF to start with. Once you get around the road blocks put in place by the Bosch/Porsche engineers , you'll have a better luck converting to a MAF. Of course this means rewriting the code to use the MAF.
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My main concern with the stock AFM is trying to find a location for it because of its size. A MAF is more compact and easier to fit in with the rest of the plumbing. If anyone can provide advice of where to fit the AFM with a supercharger installation I'm all ears.
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The hardest part would be getting the translation right in your "interceptor". I'd be interested in your approach that makes this "easy". I assume you'll be programming a microcontroller? What platform were you considering?
I've done some embedded programming over the years on Motorola, Intel and MIPS, so I'd be interested to hear what you have in mind.
Personally, I've been considering a Link Atom set-up for a forced induction set-up further down the line, and use the built in MAP sensor. Even more compact than MAF! (and cheaper, too). MAF is old hat.
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I can't see this being a problem -- it just means you'll be using ~2/3 of the range compared to the 4.5L application (assuming the same level of boost, of course.) Since you will be running closed loop, I can't imagine this slight degradation in precision being a problem. Much better to have some additional headroom rather than the other way around, of course. Even the 951 AFM maxes out at about 300HP, apparently.
The hardest part would be getting the translation right in your "interceptor". I'd be interested in your approach that makes this "easy". I assume you'll be programming a microcontroller? What platform were you considering?
I've done some embedded programming over the years on Motorola, Intel and MIPS, so I'd be interested to hear what you have in mind.
Personally, I've been considering a Link Atom set-up for a forced induction set-up further down the line, and use the built in MAP sensor. Even more compact than MAF! (and cheaper, too). MAF is old hat.![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
The hardest part would be getting the translation right in your "interceptor". I'd be interested in your approach that makes this "easy". I assume you'll be programming a microcontroller? What platform were you considering?
I've done some embedded programming over the years on Motorola, Intel and MIPS, so I'd be interested to hear what you have in mind.
Personally, I've been considering a Link Atom set-up for a forced induction set-up further down the line, and use the built in MAP sensor. Even more compact than MAF! (and cheaper, too). MAF is old hat.
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
A simple voltage interceptor http://www.jaycar.com.au/productView...T&SUBCATID=347
is all that is required to convert MAF voltage to "AFM Voltage".
I still like the Ostrich 2.0 for tuning. Not sure how that compares to the Link Atom, but I suspect it would require less wiring in.
I'm going to run next year in E class, so I'm looking at developing a system over the next year for installation towards end of next year. Still not sure what class I want to get myslelf into. 230-240hp would be top of E (very low boost - perhaps a first stage for testing - not sure how a low boost would work with parasitic drag. This raises an interesting question - could you control boost in a supercharger so you have higher boost at lower revs, and lower boost at higher revs? Perhaps a restrictor plate in the inlet?). 260-270hp would be top of D class, 300-310hp would be top of C class.
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A simple voltage interceptor http://www.jaycar.com.au/productView...T&SUBCATID=347
is all that is required to convert MAF voltage to "AFM Voltage".
is all that is required to convert MAF voltage to "AFM Voltage".
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
I'm going to run next year in E class, so I'm looking at developing a system over the next year for installation towards end of next year. Still not sure what class I want to get myslelf into. 230-240hp would be top of E (very low boost - perhaps a first stage for testing - not sure how a low boost would work with parasitic drag. This raises an interesting question - could you control boost in a supercharger so you have higher boost at lower revs, and lower boost at higher revs? Perhaps a restrictor plate in the inlet?). 260-270hp would be top of D class, 300-310hp would be top of C class.